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Cancer

​​​​​​​​​​Cancer is a group of diseases in which abnormal cells divide without control and are able to invade other tissues. There are more than 100 different types of cancer. 

Why is this important?​

Cancer is one of the most common groups​​ of chronic diseases in the United States and in Kentucky. As a state, Kentucky has one of the highest rates of new cancer cases and death from cancer in the nation.​ Cancer is the second leading cause of death in the United States and Kentucky. One in three women and one in two men will be diagnosed with cancer at some point during their life. 

What is known?​

Scientists have observed a relationship between some cancers and the presence of certain environmental pollutants. This relationship does not rule out other causes but does suggest that there are factors in the environment that may increase the risk for some cancers.

Cancers generally develop over several years and have many causes. Several factors both inside and outside the body contribute to the growth of cancer. Some of these factors include genetics, tobacco, diet, weight, physical inactivity, and excessive sunlight exposure. Other factors include exposure to ionizing radiation and environmental chemicals that may be present in the workplace, food, air, or water such as asbestos, benzene, and arsenic.

Who is at risk?​

The following list are common cancer risk factors. 

  • Old age
  • Race and ethnicity
  • Tobacco use
  • Certain environmental exposures
  • Genetics and family history
  • Certain medical conditions/diseases such as a weak immune system, diabetes, Crohn's disease, or human papillomavirus (HPV) infection

Reduce your risk:

Following these guidelines will not only reduce your risk for cancer, but improve your general health as well:

  • Do not smoke
  • Maintain a healthy weight
  • Exercise regularly
  • If you drink alcohol, only drink in moderation
  • Receive vaccines for human papillomavirus (HPV,) Hepatitis B, and Hepatitis C
  • Protect your skin from the sun by wearing proper sun-protection clothing and using plenty of sunscreen when you are outside
  • Limit your exposure to environmental risk factors, such as asbestos, radon, arsenic, and benzene
  • Get regular medical check-ups​

Resources

Types of Cancer​

Bladder cancer is more common among older persons, men, and white persons. It is common for bladder cancer to occur more than once in a person. Incidence rates of bladder cancer vary geographically, with higher rates in the northeastern United States. Known risk factors such as smoking and workplace exposures do not explain the geographic variations. The relationship between bladder cancer and drinking water contamination has been researched extensively. High levels of arsenic in drinking water have been well-established as causing cancer.

Exposure and Risk
Smoking is the greatest risk factor associated with bladder cancer. Persons who smoke have more than twice the risk for bladder cancer than non-smokers. Research indicates that smoking may cause about 30% of bladder cancers among women and 50% among men. Workplace exposures may also increase the risk for bladder cancer. Studies show that workers in the trucking, dye, rubber, textile, leather, and chemical industries have a higher risk for bladder cancer. An estimated 25% of all bladder cancers may be associated with workplace exposures. Exposure to high levels of arsenic in drinking water can cause cancer. However, scientists are not sure of the effects of exposure to low-to-moderate arsenic levels in drinking water. Long-term exposure to disinfection byproducts in drinking water may also cause a small increase in the risk for bladder cancer. Public water suppliers disinfect their water to kill viruses and bacteria. Disinfection by-products are a family of chemicals formed when drinking water disinfectants react with naturally occurring organic matter and other substances in the source water.

Prevention
Not smoking is the most important behavior to reduce bladder-cancer risk. The risk for bladder cancer among smokers who quit smoking eventually returns to normal. Workplace exposures may also increase the risk for bladder cancer. Workers in high-risk jobs should follow appropriate health and safety rules, like wearing protective equipment.​​

​The American Cancer Society reports that cancers of the brain or spinal cord account for about 1.3% of all cancers and 2.2% of all cancer-related deaths among adults and children. There are no recommendations for preventing brain or central nervous system tumors because their causes are unknown. Cancers of the brain occur in people of all ages but more frequently in two age groups:

  • Children aged younger than 15 years
  • Adults aged 65 and older

Cancers of the spinal cord are less common than cancers of the brain. Cancers of the brain and other parts of the central nervous system are more common in white persons. Cancers of the meninges, part of the central nervous system, are more common in women. Little is known about the causes of childhood and adult cancers of the brain and other parts of the central nervous system. Several studies of environmental risk factors have presented inconsistent and inconclusive results.

Exposure and Risk
About 5% of brain tumors are due to hereditary factors. Persons with rare genetic conditions such as Li-Fraumeni cancer family syndrome, tuberous sclerosis, von Recklinghausen's disease (neurofibromatosis type 1), neurofibromatosis type 2, von Hippel-Lindau disease, and familial polyposis are at greater risk for cancer of the brain and other parts of the central nervous system. Risk factors are different for children and adults. Cancerous brain and spinal cord tumors are the second most common cancers in children. Little is known about the causes of this group of diseases. Established risk factors include exposure to therapeutic doses of ionizing radiation, rare hereditary syndromes, and family history.

Prevention
Recommendations for preventing brain or nervous system tumors are undefined because their causes are unknown. Avoiding unnecessary radiation exposure can prevent many types of cancer.


​About 12,500 children and adolescents under the age of 20 years are diagnosed with cancer each year. Childhood cancers remain a leading cause of childhood deaths in the United States, despite the fact that advances in health care and treatment have dramatically increased survival from these cancers.The most common childhood cancers are leukemias, cancers of the blood cells. There are different kinds of childhood leukemia. The most common kinds are acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML). Brain and other nervous system cancers are the second most common types of childhood cancers. Of the 12 major types of childhood cancer, leukemias and brain and other nervous system cancers account for 40% of all cases among children less than 20 years of age. Other childhood cancers, in decreasing order of occurrence, include lymphomas, sympathetic nervous system cancers, soft tissue sarcomas, renal tumors (Wilms tumor and renal carcinoma), bone tumors (osteosarcoma and Ewing sarcoma), malignant germ cell tumors, retinoblastomas, hepatic tumors, and other malignancies. Researchers have studied childhood cancers for many years but still do not know a lot about what causes them. Finding the causes of childhood cancers is challenging because cancer in children is rare and each type of cancer may have different factors that lead to its development. It is especially difficult to identify environmental factors related to childhood cancer because environmental exposures to the parent, the child in the womb, or the child after birth may play a role. Childhood cancers, like adult cancers, may be the result of a mix of genetic, environmental, and behavioral causes, not just one factor by itself.

Exposure and Risk
Risk factors are different for children and for adults and vary for specific types of cancer. For most childhood cancers, risk factors remain unclear.

Leukemias
As with most cancers, the cause of most types of leukemia is unknown.

Acute Lymphocytic Leukemia (ALL)
Known risk factors include:
  • Sex: Overall, males are more likely to develop ALL than females.
  • Age: Most new cases happen in children between the ages of 2 and 5 years.
  • Race: White children are almost two times more likely to develop ALL than black children.
  • Socioeconomic status (SES): Children with a higher SES have an increased risk for ALL.
  • Ionizing radiation.
  • Genetic conditions: Children with the following genetic conditions are at increased risk:
    • Down syndrome - Children with Down syndrome are 20 times more likely to develop ALL.
    • neurofibromatosis
    • Shwachman syndrome
    • Bloom syndrome
    • ataxia telangiectasia
    • Langerhans cell histiocytosis
    • Klinefelter syndrome
Acute Mylelogenous Leukemia (AML)
Risk factors for AML are different than those for ALL. Known risk factors include:
  • Race: Hispanic children are at highest risk.
  • Chemotherapy: Children who are exposed to alkylating agents or epipodophyllotoxins during chemotherapy treatment are at increased risk.
  • Ionizing radiation.
  • Genetic conditions: Children with the following genetic conditions are at increased risk:
    • Down syndrome - Children with Down syndrome are 20 times more likely to develop ALL.
    • neurofibromatosis
    • Shwachman syndrom
    • Bloom syndrome
    • Familial monosomy 7
    • Kostmann granulocytopenia
    • Fanconi anemia
A number of other factors have been investigated to determine their relationship with ALL and AML but any evidence has been inconsistent and limited. These factors include exposures to specific chemicals, paternal occupation, paternal smoking, maternal alcohol use, and factors related to birth. International variation in the occurrence of childhood leukemias as well as studies finding increases in risk with population growth due to in- migration in areas have lead to the theory that an infectious agent may play a role; however, studies have not been able to confirm the presence of an infectious agent.

Brain and other Nervous System Cancers
Very little is known about the causes of brain and other nervous system cancers. Known risk factors include:
  • Sex: Overall, males are more likely to develop brain and other nervous system cancers than females.
  • Race: White children are more likely to develop brain and other nervous system cancers than black children.
  • Radiation therapy
  • Rare hereditary conditions: Children with the following genetic conditions are at increased risk:
    • Li-Fraumeni syndrome
    • neurofibromatosis
    • Tuberous sclerosis
    • Nevoid basal cell syndrome
    • Turcot syndrome
A number of environmental factors have been investigated, but more research is needed to determine how the environment relates to brain and other nervous system cancers in children. There is some evidence that having a parent who is a farm worker or living on a farm may be associated with these cancers.

Prevention
Cancer prevention measures are difficult to develop for children because very little is known about what causes childhood cancers. Rare genetic conditions seem to be factors for cancers developing in children. Children's bodies are also more sensitive to ionizing radiation. Ask your doctor or your child's pediatrician for specific health recommendations.


Colorectal cancer (colon cancer) is a disease in which cells in the colon or rectum grow out of control. Most types of colorectal cancer start as a growth on the inner lining of the colon or rectum. These growths are called polyps. If cancer forms in a polyp, it can grow into the wall of the colon or rectum over time. Colorectal cancer is the fourth most common cancer in men and women (not including skin cancer). Colorectal cancer is also the fourth leading cause of cancer-related deaths in the United States. Lifestyle factors increase the risk of colon cancer and include: lack of physical activity, obesity, alcohol and tobacco consumption.

Exposure and Risk
The risk of colorectal goes up as a person ages. It is much more common after the age of 50. The following factors also increase the chances for colorectal cancer: 
  • a personal history of colorectal polyps or colorectal cancer
  • a personal history of inflammatory bowel disease (including either ulcerative colitis or Crohn’s Disease)
  • a family history of colorectal cancer or adenomatous polyps
  • having an inherited syndrome such as Lynch Syndrome and Familial Adenomatous Polyposis
  • having Type Two Diabetes​
Prevention
The best way to reduce your risk for colorectal cancer is to get screened for it regularly, starting at age 45. Medical experts also recommend a diet low in animal fats and high in fruits, vegetables, and whole grains help reduce the risk of colorectal cancer. Studies also suggest that people can reduce their risk of colorectal cancer by having more physical activity, keeping a healthy weight, limiting alcohol consumption, and avoiding tobacco products.

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Esophageal cancer is a cancer that forms in the esophagus, a muscular tube in the chest that is part of the digestive tract. This tube plays an important role in the digestive system by moving food from the mouth to the stomach. The walls of the esophagus have several layers of tissue, which are built of different types of cells. Because there are two kinds of cells that can line the esophagus, there are two main types of esophageal cancer:
  • adenocarcinoma
  • squamous cell carcinoma

These two kinds of esophageal cancer have different risk factors and affect people in different ways. Each year in the United States, about 15,000 people in the United States are diagnosed with esophageal cancer. On the Tracking Network, you can also find data on the prevalence of smoking, which might be helpful when looking at the incidence of esophageal cancer. Research is needed to better understand the relationship between the environment and esophageal cancer, which may help determine other potential risk factors for this disease.

Exposure and Risk
Tobacco
Smoking is the most consistent risk factor for esophageal cancer. Smokers are five times more likely to develop esophageal cancer than non-smokers.

Gender
Men have a higher risk for developing esophageal cancer. This disease is 3 to 4 times more common among men than among women. Survival rates for esophageal cancer are higher among men than women and higher among whites than African Americans.

Race/Ethnicity
There are significant differences in the number of diagnoses of adenocarcinoma and squamous cell carcinoma among people of different races and ethnicities. Adenocarcinoma is the most common type of esophageal cancer among whites, while squamous cell carcinoma is more common in African Americans.

Age
The risk for developing esophageal cancer increases with age and is very low among children and young adults. Less than 15% of cases are in people younger than age 55. Although adenocarcinoma and squamous cell carcinoma have many similar risk factors, there are some risk factors that are unique to each type of cancer. Adenocarcinoma may be related to
  • having acid reflux (the backward flow of stomach acid)
  • having a disease of the lower esophagus known as Barrett esophagus
  • being obese

Squamous cell carcinoma may be related to being a heavy drinker of alcohol.

Prevention
You may be able to reduce your risk of developing esophageal cancer by avoiding or changing behaviors that are known risk factors for the disease. These healthy behaviors may help prevent esophageal cancers:
  • Don't smoke or use any tobacco products.
  • Limit your alcohol consumption. If you do choose to drink alcohol, drink in moderation
  • Maintain a healthy body weight.



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Breast cancer is the most commonly diagnosed cancer in women in the United States. Breast cancer will develop in approximately one in eight women during their lifetime. The incidence of this disease has changed very little in recent years. The disease usually occurs in women, but men can have breast cancer too. Exposure to chemicals such as poly aromatic hydrocarbons, benzene, and organic solvents and secondhand smoke have been suspected in causing breast cancer, but the evidence is weak and more research is needed. Pesticides and industrial products in food packaging and consumer products concern researchers because of their pervasive presence in the environment, ability to be absorbed by fat, and potential to act as endocrine disruptors. An endocrine disruptor is a synthetic chemical that when absorbed into the body either mimics or blocks hormones and disrupts the body's normal functions. Research continues into the link between these chemicals and breast cancer.

Exposure and Risk
The exact causes of breast cancer are unknown; however, women in certain categories are at increased risk for breast cancer. Known risk factors include:
  • Older age
  • White ethnicity
  • Obesity (after menopause)
  • Dense breast tissue (after menopause)
  • High estrogen levels
  • Unusually tall
  • Early onset of menstruation
  • Later age pregnancy
  • Having no or few children
  • Late onset of menopause
  • Family history of breast cancer
  • Certain genetic mutations
  • Certain types of benign breast disease
  • History of breast cancer
  • Post-menopausal hormone use
  • Heavy alcohol consumption
  • Cigarette smoking
  • Exposure to secondhand cigarette smoke
  • Current or recent use of birth control pills
  • Low levels of physical activity
  • Never breast feeding or short duration of breast feeding
  • Exposure to radiation to the chest
  • Prenatal exposure to diethylstilbestrol (DES)
Prevention
Among women whose risk is higher than average, certain drugs may help prevent breast cancer. All women should discuss their risk and screening or prevention options with their doctor.


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Kidney cancer is a cancer that forms in tissues of the kidneys. Some types of kidney cancer include:
  • renal cell carcinoma; cancer that forms in the lining of very small tubes in the kidney that remove waste from blood;
  • renal pelvis carcinoma; cancer that forms in the center of the kidney where urine collects; and
  • Wilm's tumor; a type of kidney cancer that usually develops in children younger than age 5.
Kidney cancer is among the 10 most common cancers in both men and women.

Research is needed to better understand the connection between the environment and kidney cancer. However, the kidney's main function of removing waste from our blood puts it at higher risk to the effects of harmful substances in our body. This includes environmental contaminants we come into contact with during our lifetimes. Studies have shown that some people exposed to trichloroethylene (TCE) or arsenic, through contaminated drinking water for example, may be at an increased risk for kidney cancer. Kidney cancer is among the 10 most common cancers in both men and women.

Exposure and Risk
People with the following risk factors may be more likely than others to develop kidney cancer:
  • smoking
  • exposure to certain hazardous substances, such as arsenic, asbestos, cadmium, some herbicides, benzene, and trichloroethylene (TCE)
  • obesity
  • high blood pressure
  • family history of kidney cancer
Prevention
You may be able to reduce your risk for kidney cancer by avoiding known risk factors for the disease. Cigarette smoking is responsible for a large number of cases, and stopping smoking may lower your risk. Maintaining a healthy weight, exercising, choosing a diet high in fruits and vegetables, and getting treatment for high blood pressure may also lower your chance of getting this type of cancer. Finally, avoid workplace exposure to large amounts of harmful substances such as cadmium, asbestos, and organic solvents.


​Laryngeal cancer is a cancer that forms in the tissues of the larynx. The larynx is also known as the voice box. It is about the size of a lime and contains the vocal cords that help you produce sounds and talk. The larynx also helps control other important functions like breathing and swallowing. Each year, about 10,000 men and 2,500 women in the United States are diagnosed with this disease. Most of these persons will be over 65 years old.

Laryngeal cancer is most common among
  • older persons
  • men
  • African Americans
Some studies have shown that long-term exposure to secondhand smoke may increase a person's risk for laryngeal cancer. However, the impact of secondhand smoke on laryngeal cancer requires further study. Research is needed to better understand the relationship between the environment and laryngeal cancer, which may help determine other potential risk factors for this disease.

Exposure and Risk
Tobacco
Tobacco use is the single most important risk factor for developing this cancer. Since the 1950s, studies have shown a consistent link between cigarette smoking and laryngeal cancer. Heavy smokers who have smoked tobacco for a long time are most at risk for developing this disease. Incidence rates of laryngeal cancer are falling on average 2.5% a year for the past 10 years, in part, because fewer people are smoking. On the Tracking Network, you can also find data on the prevalence of smoking, which might be helpful when looking at the incidence of laryngeal cancer.

Alcohol
People who consume moderate to heavy amounts of alcohol also have a higher risk for developing laryngeal cancer. This risk increases even more for people who combine heavy drinking with heavy smoking.

Prevention
You may be able to reduce your risk for laryngeal cancer by avoiding known risk factors for the disease. These healthy behaviors may help prevent laryngeal cancer:
  • Don't smoke or use any tobacco products
  • Limit your alcohol consumption. If you do choose to drink alcohol, drink in moderation
​Leukemia is cancer of the blood cells. When leukemia develops, the body makes many abnormal blood cells.

Leukemia comprises a group of diseases that includes four major types:
  • Acute myeloid
  • Chronic myeloid
  • Chronic lymphocytic leukemia (primarily adult diseases)
  • Acute lymphocytic leukemia (a childhood disease)
Sometimes considered a children's disease, leukemia usually occurs in adults older than 65 years. The relationship between leukemia and the environment is still not well understood; however, studies have determined that exposure to high levels of ionizing radiation has been linked to specific types of leukemia in both adults and children.

Exposure and Risk
As with most cancers, the cause of most leukemias is unknown. Generally, some risk factors include:
  • High doses of ionizing radiation
  • Genetic abnormalities, including Downs syndrome
  • Rare viruses
  • Long-term benzene exposure
  • Smoking
  • Chemotherapy drugs known as "alkalating agents"
The relationship of these factors may depend on the type of leukemia. Moreover, adult leukemia risk factors differ from those of children. For adult-onset leukemia, the most firmly established environmental risk factor is exposure to ionizing radiation. Benzene, agricultural exposures, and smoking also have been linked to elevated risk. For acute lymphocytic leukemia in children, their exposure to ionizing radiation and a parent's exposure to pesticides and other chemicals may increase risk.

Prevention
Not smoking can reduce the risk for acute myeloid leukemia. Avoiding unnecessary radiation exposure can prevent many types of cancer.

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Liver cancer is a disease in which cancer forms in the liver cells. Liver cancer is very rare in the United States (U.S.). Only 1.8% of new cancer cases every year are liver cancer. However, the percentage of Americans developing liver cancer has been rising slowly for several decades. The liver plays an important role in removing harmful substances from our blood. This includes environmental contaminants people come into contact with during their lifetimes. Even though the liver usually does a good job at removing those harmful substances, certain chemicals have been shown to damage the liver. For example, studies have shown that some people who drink water containing high levels of arsenic over many years could experience health effects including liver cancer.

Exposure and Risk
Certain people are at increased risk for liver cancer. Globally, 80% to 95% of all liver cancer cases are associated with hepatitis B or hepatitis C viruses.
Other known risk factors include:
  • Gender
    • Some types of liver cancer are more common in men than in women
  • Race/ethnicity
    • In the U.S., Asian Americans and Pacific Islanders have the highest rates of liver cancer, followed by African Americans, American Indians/Alaska Natives and Hispanics/Latinos, and Caucasians.
  • Chronic viral hepatitis
    • The most common risk factor for liver cancer is chronic infection with the hepatitis B or C virus.
  • Underlying health conditions
    • Cirrhosis, or scarring of the liver, increases a person's risk of liver cancer. The majority of people with liver cancer have some evidence of cirrhosis.
  • Behaviors
    • Heavy alcohol use has been linked to an increased risk of liver cancer by causing cirrhosis.
    • Evidence suggests that smokers are at increased risk for liver cancer.
    • Eating foods tainted with aflatoxin. This is a poison from a fungus that can grow on foods, such as grains and nuts, that have not been stored properly.
  • Exposure to arsenic
    • Drinking water contaminated with arsenic, increases the risk of some types of liver cancer.
Prevention
You may be able to reduce your risk for many types of liver cancer by avoiding known risk factors for the disease, such as:
  • avoiding becoming infected by hepatitis and treating hepatitis infections
  • limiting alcohol and tobacco use
  • treating other diseases that increase liver cancer risk
  • limiting exposure to cancer-causing chemicals
  • completing vaccination for hepatitis B



​Lung cancer is the leading cause of cancer deaths in the United States. Lung cancer forms in the tissue of the lung, usually in the cells lining the air passages. Cigarette smoking is the single most crucial risk factor for, and leading cause of, lung cancer. Exposure to radon is the second leading cause of lung cancer.

The International Agency for Research on Cancer (IARC) has identified the following substances as lung cancer-causing agents:
  • Arsenic
  • Asbestos
  • Bischloromethlyl ether
  • Chromium
  • Nickel
  • Polycyclic aromatic compounds
  • Radon
  • Vinyl chloride

A history of certain lung diseases also increases the risk for lung cancer. Diets low in fruits and vegetables might increase the risk of lung cancer in persons who smoke.
Environmental tobacco smoke (also called secondhand smoke) is a well-established cause of lung cancer. Air pollution and diesel exhaust have also been shown to have a slight increase in lung cancer morbidity and/or mortality. However, the impact of outdoor air pollution on lung cancer needs further study.

Exposure and Risk
Cigarette smoking is the most common cause of lung cancer. It remains the leading preventable cause of death in the United States. Even for nonsmokers, exposure to environmental tobacco smoke increases the risk for lung cancer. The 2006 Surgeon General's ReportExternal Web Site Icon says the evidence suggests that secondhand smoke exposure can cause lung cancer in lifetime nonsmokers, regardless of where the exposure occurs (e.g., home, work, restaurants). Every year, about 3,000 nonsmokers in the United States die from lung cancer caused by secondhand smoke. There is no risk-free level of secondhand smoke exposure.
Studies also indicate that exposure to certain chemicals may increase the risk for lung cancer, especially among smokers. These chemicals include:
  • Arsenic
  • Chromium
  • silica
  • substances used or produced in foundries
  • substances produced by processing coal
Radon exposure is the second leading cause of lung cancer after tobacco smoke. Radon is a naturally occurring, colorless, odorless, tasteless, radioactive gas that can be found throughout the United States. It can infiltrate homes, offices, and schools and cause high indoor radon levels. The greatest exposure likely occurs in homes where most personal time is spent.

Prevention
Not smoking is the most effective way to reduce the risk for lung cancer. Limiting exposure to environmental tobacco smoke and testing homes for radon also reduce the risk for lung cancer. Eating fresh fruits and vegetables may also decrease risk, as well as help prevent other diseases. Also, workers in high risk jobs should follow appropriate health and safety rules, like wearing protective equipment.


​Melanoma is a type of cancer in skin cells that produce the pigment that colors the skin (melanin). It is the most dangerous and one of the most common cancers among adolescents and adults under 40. If this type of skin cancer is found early, it can be cured. However, melanoma can spread through the body much more quickly than other types of skin cancers and can cause death.
Between 65 and 90% of melanomas are caused by exposure to ultraviolet (UV) radiation from sunlight. Small amounts of UV radiation are good for people and needed for the body to produce vitamin D. But too much exposure to the sun's rays can cause skin damage such as sunburn, wrinkles, and skin cancers. Peoples' behavior in the sun is believed to be a major reason for the rise in skin cancer rates, including melanoma, over the last few decades.

Exposure and Risk
Most melanomas are caused by exposure to ultraviolet (UV) radiation from the sun. Everyone is exposed to UV radiation from the sun. However, a growing number of people are being overexposed to sun rays and other sources of artificial UV radiation used in industry and other settings such as indoor tanning (using a tanning bed, booth, or sunlamp). When UV rays reach the skin's inner layer, the skin makes more melanin. It moves toward the outer layers of the skin which causes a tan. A tan does not indicate good health. A tan is a response to injury, because skin cells are signaling that they have been hurt by UV rays by producing more pigment. People burn or tan depending on:
  • their skin type
  • the time of year
  • how long they are exposed to UV rays.
People with certain risk factors are more likely than others to develop melanoma, such as:
  • a lighter natural skin color
  • family history of skin cancer
  • a personal history of skin cancer
  • exposure to the sun through work and play
  • a history of sunburns
  • a history of indoor tanning
  • skin that burns, freckles, reddens easily, or becomes painful in the sun
  • blue or green eyes
  • blond or red hair, and
  • certain types and a large number of moles
Prevention
Protecting yourself from ultraviolet (UV) radiation is important all year round, not just during the summer or at the beach. UV rays from the sun can reach you on cloudy and hazy days, as well as bright and sunny days. UV rays also reflect off of surfaces like water, cement, sand, and snow. Indoor tanning also exposes people to UV radiation.
You may be able to reduce your risk of melanoma by following these steps:
  • seek shade, especially at midday
  • wear clothing to protect exposed skin
  • wear a hat with a wide brim to shade the face, head, ears, and neck
  • wear sunglasses that wrap around and block as close to 100% of both UVA and UVB rays as possible
  • use sunscreen with sun protective factor (SPF) of 15 or higher, and both UVA and UVB (broad spectrum) protection
  • avoid indoor tanning
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Mesothelioma is a rare form of cancer which is almost always caused by exposure to asbestos. Asbestos is the name given to a group of minerals that occur naturally in the environment as bundles of fibers that can be separated into thin, durable threads. These fibers are resistant to heat, fire, and chemicals and do not conduct electricity. For these reasons, asbestos has been used widely in many industries.

Being exposed to asbestos particles in the air is the major risk factor for mesothelioma. This type of cancer happens when harmful, or malignant, cells develop in the protective lining that covers most of the body's internal organs. The most common sites for mesothelioma are in the chest or belly, where cells become abnormal in response to asbestos fibers that have embedded in
  • the outer lining of the lungs or chest cavity
  • the lining of the abdominal cavity (belly)
  • the sac that surrounds the heart
As the link between asbestos and mesothelioma became clearer in the late 1970s, use of asbestos went down, and most use stopped by 1989. Experts believe that mesothelioma incidence rates are not going up because of the drop in asbestos use after this link to cancer was discovered.

Exposure and Risk
The main risk factor for developing mesothelioma is exposure to asbestos. Most cases of mesothelioma have been linked to asbestos exposure in the workplace. This exposure may result from the following:
  • mining or milling materials
  • fireproofing the superstructures of building or ships
  • maintaining railroad or automotive brakes
  • insulating pipes and ductwork
  • release of materials to the air by water or demolition
  • being near a road paved with crushed serpentine stone
  • handling the work clothes of asbestos miners or millers
Prevention
The best way to reduce your risk of mesothelioma is to limit your exposure to asbestos in homes, in public buildings, and at work.
If you live in an older home, there may be insulation with asbestos or other materials. An expert should check your home to find out if there is any asbestos, whether it poses any risk to you, and if so, the best way to take care of it. If there is a chance you might be exposed to asbestos at work, then you should use all protective equipment and follow safety procedures for working around asbestos. For more information, please visit The Agency for Toxic Substances and Disease Registry


​Non-Hodgkin's lymphomas are a group of cancers that start in lymphoid tissue, also called lymph or lymphatic tissue. The causes of Non-Hodgkin lymphomas are mostly unknown. Specific viruses, immune deficiency, and specific autoimmune conditions have been implicated in increased risk. However, some environmental issues, including exposures to pesticides and solvents, are also being investigated.Exposure and Risk
Most patients with Non-Hodgkin lymphomas have no known risk factors; however, a few risk factors that may make a person more likely to get Non-Hodgkin lymphomas have been determined. These factors include:

Age
  • Getting older is a strong risk factor for this disease; most cases occur in people aged 60 years or older.

Exposure to Certain Chemicals
  • Some studies have suggested that chemicals such as benzene and certain herbicides and insecticides may be linked with an increased risk for Non-Hodgkin's lymphomas. More research is needed to determine the validity of these studies.

Treatment with Chemotherapy Drugs
  • Some chemotherapy drugs used to treat cancers can increase the risk for leukemia or Non-Hodgkin lymphomas many years later. For example, patients who have been treated for Hodgkin disease have an increased risk for Non-Hodgkin lymphomas later in life.
  • It is not clear whether this increased risk is an effect of the treatment or the inherent course of disease.

Radiation Exposure
  • Survivors of atomic bombs or nuclear reactor accidents have a higher risk for many kinds of cancer, including Non-Hodgkin lymphomas.
  • Persons treated with radiation therapy for cancers also have a slightly higher risk for Non-Hodgkin lymphomas later in life.
  • The risk is greater if both radiation and chemotherapy were used during the cancer treatment.

Weakened Immune System
  • People with weakened immune systems are at increased risk for Non-Hodgkin lymphomas. For example, patients who receive organ transplants (kidney, heart, liver) are treated with drugs that suppress their immune system to prevent it from attacking the new organ. The exact risk depends on the type and dosage of drugs that were used.
  • Sometimes children are born with a dysfunctional immune system. These children have a higher risk for developing Non-Hodgkin lymphomas in childhood or as young adults.
Autoimmune Diseases
  • In these diseases, the immune system is dysfunctional. The immune system responds to the person's own body as foreign and tries to destroy it, as it would any foreign substance.
  • Some autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus (SLE) have been linked to an increased risk for Non-Hodgkin lymphomas.
Certain infections
  • HIV infection (also known as the AIDS virus)
  • HTLV-1 (a virus in the same family as HIV)
  • Epstein-Barr virus (mainly in patients infected with HIV)
  • Helicobacter pylori (a type of bacteria that causes stomach ulcers)
Body Weight and Diet
  • Being very overweight (obese) might increase the risk for Non-Hodgkin lymphomas.
  • Some studies have suggested that a diet high in vegetables may lower the risk for Non-Hodgkin lymphomas; more research is needed to confirm this.
Prevention
Most people who have Non-Hodgkin lymphomas have no known risk factors, and the cause of their cancer is unknown. The best way to prevent this cancer is to reduce known risk factors, such as reducing the spread of HIV, which causes AIDS. HIV is spread among adults usually through sex or sharing contaminated needles by IV drug users. Treating AIDS with new anti-HIV drugs appears to reduce the risk for Non-Hodgkin lymphomas.
By exploring the relationship between Helicobacter pylori and lymphoma, some methods to prevent Non-Hodgkin lymphomas may be discovered. More research is needed to discover these possibilities.
Doctors are also exploring cancer treatment and organ transplant methods that reduce the risk of lymphoma. However, in the case of life-threatening diseases, the risk of acquiring lymphoma later must be balanced against the immediate need to treat the critical disease.

​Oral and pharyngeal cancers, which are cancers of the mouth and throat, include cancers in the
  • tongue
  • gum
  • floor of mouth
  • palate
  • lip
  • oral cavity
  • pharynx
  • other areas of the mouth
Each year in the United States, more than 36,000 new cases of oral and pharyngeal cancer are diagnosed and over 8,000 deaths due to oral cancer occur. The 5-year survival rate for these cancers is about 62 percent. Studies have shown that exposure to secondhand smoke increases a person's risk for developing oral and pharyngeal cancers. Research is needed to better understand the relationship between the environment and oral and pharyngeal cancers, which may help determine other potential risk factors for this disease.

Exposure and Risk
Tobacco and Alcohol
Tobacco use and alcohol consumption are well-known risk factors for oral and pharyngeal cancers, regardless of the type of tobacco product used or alcoholic beverage consumed. Three out of four people with oral cancer have used tobacco, alcohol, or both. On the Tracking Network, you can also find data on the prevalence of smoking, which might be helpful when looking at the incidence of oral and pharyngeal cancers.

Gender
Men are at a higher risk for developing oral and pharyngeal cancers, and are more than two times more likely to be diagnosed with these diseases than women. Each year more than 25,000 men are diagnosed with oral cancer.

Race/ethnicity
Among men, black men have the highest oral cancer death rate. The second highest death rate is in white men.

Age
Cancers of the mouth and throat usually take many years to develop, so they are not common in young people. The risk of developing oral and pharyngeal cancer greatly increases with age. Most people who are diagnosed with oral and pharyngeal cancers are over 60 years old.
People with the following risk factors may be more likely to develop oral and pharyngeal cancer:
  • smoking and chewing tobacco
  • being a heavy drinker of alcohol
  • having a human papillomavirus (HPV) infection
  • having a personal history of oral cancer
  • having diets low in fruits and vegetables
Prevention
You may be able to reduce your risk of developing oral and pharyngeal cancers by avoiding or changing behaviors that are known risk factors for these diseases. These healthy behaviors may help prevent oral and pharyngeal cancers:
  • Don't smoke or use any tobacco products.
  • Avoid exposure to secondhand smoke.
  • Limit your alcohol consumption. If you do choose to drink alcohol, drink in moderation.
  • Limit exposure to ultraviolet (UV) light from natural sunlight and artificial sunlight (such as tanning beds), which can cause cancer in the lip.
  • Choose a diet high in fresh fruits and vegetables, which may also help prevent other diseases.
  • Maintain a healthy body weight.



​Pancreatic cancer is a cancer that forms in the pancreas, the thin, pear-shaped gland behind the stomach. The pancreas plays an important role in the digestive system by producing fluids to help break down food and hormones to control blood sugar levels.
Pancreatic cancer is among the ten most common cancers for both men and women. It is the cause of 7% of all cancer deaths. It ranks fourth as a cause of cancer death in both men and women in the United States each year. Incidence rates of pancreatic cancer have been rising by almost 1.2% each year over the last 10 years. Early stage pancreatic cancer usually has no symptoms and spreads quickly throughout the body, making it difficult to detect and harder to treat when it is found in its later stages.
The causes of pancreatic cancer are not well understood. According to the American Cancer Society heavy exposure at work to certain pesticides, dyes, and chemicals may increase the risk of developing pancreatic cancer. Research is needed to better understand the relationship between the environment and pancreatic cancer, which may help determine other potential risk factors for this disease.

Exposure and Risk
Tobacco
Tobacco use is the most consistent risk factor for pancreatic cancer. About 20% of all pancreatic cancer cases are attributable to cigarette smoking. Smokers are about two times more likely to develop pancreatic cancer than non-smokers. Studies have shown that the risk for developing this type of cancer gets lower over time after you quit smoking.

Gender
Men have a higher risk for developing pancreatic cancer than women. This disease is about 30% more common in men than in women.

Race/ethnicity
In comparison to other races and ethnicities, African Americans are at a slighter higher risk for developing pancreatic cancer throughout their lives.

Age
Age is the most reliable and important known predictor of pancreatic cancer. The risk of developing pancreatic cancer greatly increases with age. Nearly 70% of all pancreatic cancer patients are at least 65 years old. Across all races, ethnicities, and genders, the incidence of this disease increases significantly after age 50.
People with the following risk factors may be more likely to develop pancreatic cancer:
  • smoking cigarettes or using tobacco products
  • being obese
  • having diabetes
  • having chronic pancreatitis.
  • having certain hereditary conditions
  • having a family history of pancreatic cancer
Prevention
You may be able to reduce your risk of developing pancreatic cancer by avoiding or changing behaviors that are known risk factors for the disease. These healthy behaviors may help prevent pancreatic cancer:
  • Don't smoke or use any tobacco products.
  • Maintain a healthy body weight.



​Thyroid cancer is cancer that develops in the small, butterfly-shaped gland below the Adam's apple that regulates the body's metabolism, controlling everything from heart rate to how fast the body burns calories.
Thyroid cancer has a lower fatality rate than most cancers. Since 1973, a 2.4 fold increase in the incidence of this disease has occurred. Much of this is attributable to improved detection of the disease by thyroid ultrasound and ultrasound-guided fine needle aspiration rather than an increase in occurrence. Over 38,000 U.S. residents were diagnosed with thyroid cancer in 2008. Thyroid cancer is much more likely to occur in women and people between the ages of 20 and 55. The American Cancer Society states, "nearly 2 out of 3 cases are found in people between the ages of 20 and 55."
The excessive risk for thyroid cancer associated with exposure to external ionizing radiation has been well-established. No other environmental chemicals or physical agents have been associated with this cancer. Other risk factors for this cancer include:
  • dietary factors, especially iodine intake
  • hormonal and reproductive factors
  • benign thyroid nodules and goiter
  • hereditary conditions
  • gender and age
Exposure and Risk
Although a person with thyroid cancer may have a risk factor, the degree to which that risk factor contributes to the cancer may be difficult to determine. A few risk factors that increase the likelihood to develop thyroid cancer have been established. These include:

Gender and Age
  • For undetermined reasons, thyroid cancers occur about 3 times more often in women.
  • Thyroid cancers can occur at any age but most cases of them occur between the ages of 20 and 55 years.

Diet Low in Iodine
  • Some types of thyroid cancers are more common in areas of the world where diets are low in iodine.
  • In the United States, dietary iodine intake is sufficient because iodine is added to table salt and foods.
Radiation
  • Exposure to high levels of radiation during childhood has been proven to increase the risk for thyroid cancer. Sources of exposure include certain medical treatments and radiation fallout from power plant accidents or nuclear weapons.
    • X-ray treatments prescribed for conditions like childhood acne or ringworm of the scalp from the 1920s to the 1950s increased the risk for thyroid cancer.
    • A history of head or neck radiation treatments in childhood increases the risk for thyroid cancer.
    • Radiation therapy in childhood for some cancers such as Hodgkin's disease also increases risk.
    • Several studies suggested an increased risk of thyroid cancer in children because of exposure to radioactive iodine (I-131) in fallout from nuclear weapons or power plant accidents such as the Chernobyl accident. Some radioactive fallout occurred over certain regions of the United States after nuclear weapons testing in western states during the 1950s. This exposure was significantly lower than that measured around Chernobyl. At such low exposures, a higher risk of thyroid cancer has not been proven.
Hereditary Conditions
  • Medullary thyroid cancer (MTC): About 1 of 5 MTCs is caused by an inherited abnormal gene.
  • Other thyroid cancers: Higher rates of the disease occur among persons with uncommon genetic conditions such as Gardner syndrome, Cowden disease, and familial adenomatous polyposis (FAP).
  • Papillary and follicular thyroid cancers: These cancers seem to run in some families without a known inherited syndrome. This trend may account for about 5% of all thyroid cancers. The genetic basis for these cancers is undecided.
Prevention
Most people with thyroid cancer have no known risk factors; therefore it is not possible to prevent the disease in those instances. Because of the availability of genetic blood tests, most of the hereditary cases of Medullary thyroid cancer (MTC) can be either prevented or treated early. If the disease is diagnosed, the patient's family members can be tested also. If a family history of MTC exists, a doctor who is familiar with the latest advances in genetic counseling and genetic testing for this disease should be consulted. Removing the thyroid gland in children who carry the abnormal gene will prevent a cancer that might be fatal. In some radiation emergencies, public health or emergency management officials may advise the use of Potassium Iodide (KI) to protect the thyroid gland from radioactive iodine.